Generally, silicide regions may be formed on a substrate in order to lower the resistance between source and drain regions within the substrate and a contact that may be formed to provide a connection to the source and drain regions. The silicide regions may be manufactured by initially forming a layer of material, such as a layer of a metallic material, over the substrate. This layer of material is also formed in physical contact with the substrate where the silicide regions are desired to be located.
This structure, with the layer of material over and in contact with the substrate, may then be heated to diffuse the layer of material into the substrate and also to diffuse the substrate into the layer of material, wherein the layer of material and the substrate diffuse and react with each other to form a substrate/material compound, thereby forming the silicide region. Once the silicide region has been formed, any excess material that has not reacted with the substrate may be removed using, for example, a selective etching process that can remove the unreacted material without significantly removing the silicide.
Once the silicide has been formed, the composition of the silicide may be tested, for example, using a secondary ion mass spectrometry (SIMS) test. In such a test the surface of the silicide may be bombarded by ions, which impact upon the surface of the silicide to break apart the surface and slowly sputter the surface of the silicide away from the remainder of the substrate. The profile of the surface (and, if charted over time, the overall profile of the silicide) may be obtained by measuring, as a function of time, the secondary ion yield of the surface as it is sputtered. This sputtering may then be correlated to the amount of material removed and can be used to provide a composition profile of the silicide across the depth of the silicide.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.